Crystal structures can be divided into 32 classes, or point groups, according to the number of rotational axes and reflection planes they exhibit that leave the crystal structure unchanged. Twenty of the 32 crystal classes are piezoelectric. All 20 piezoelectric classes lack a center of symmetry. Any material develops a dielectric polarization when an electric field is applied, but a substance which has such a natural charge separation even in the absence of a field is called a polar material. Whether or not a material is polar is determined solely by its crystal structure. Only 10 of the 32 point groups are polar. All polar crystals are pyroelectric, so the 10 polar crystal classes are sometimes referred to as the pyroelectric classes. Polar crystals have opposite charges on opposite crystal faces.
Of the polar crystal minerals, tourmaline is a group name for about thirteen species of minerals that exhibit piezoelectrical characteristics. The Tourmaline group are silicated minerals containing boron, and they belongs to a trigonal or hexagonal, hemimorphic, hemihederal group. Its hemimorphisms are asymmetric with respect to the major axis, and its chemical formulae are complicated. A typical formula is:WX3Y6{NaX3Al6(BO3)3Si6016(O,0H,F)4} Where W═Ca, K, NaX═Al, Fe2+, LiY═Al, CR3+, Fe3+Natural tourmaline occurs in crystalline schist, gneiss, contact metamorphic rocks, and pegmatite. Tourmaline is capable of being obtained in large crystalline form.
The following is a set of data for tourmaline taken from the web site http://en.wikipedia.org/wiki/Tourmaline:
CategoryMineral GroupGeneralNa(Al,Fe,Li,Mg,Mn)M3Al(Si6O18)(BO3)3(OH,F)4ChemicalformulaIdentificationColorMost commonly black, but can range frombrown, violet, green, pink, or in a dual-coloredpink and green.Crystal habitParallel and elongated. Acircular prisms,sometimes radiating. Massive. Scattered grains(in granite).Crystal systemTrigonalCleavageGood to poor prismatic. Poor rhombohedralFractureSubconchoidal to evenMohs Scale7-7.5hardnessLusterVitreous, sometimes resinousRefractive indexnω = 1.635-1.675 nε = 1.610-1.650PleochroismNoneStreakColorlessSpecific gravity3.02-3.26The 14 recognized minerals in the group (end memberformulas)ElbaiteNa(Li1.5,Al1.5)Al6Si6O18(BO3)3(OH)4SchorlNaFe2+3Al6Si6O18(BO3)3(OH)4DraviteNaMg3Al6Si6O18(BO3)3(OH)4ChromdraviteNaMg3Cr6Si6O18(BO3)3(OH)4OleniteNaAl3Al6Si6O18(BO3)3O3OHBuergeriteNaFe3+3Al6Si6O18(BO3)3O3FPovondraiteNaFe3+3(Fe3+4Mg2Si6O18(BO3)3(OH)3OVanadiumdraviteNaMg3V6Si6O18(BO3)3(OH)4LiddicoatiteCa(Li2Al)Al6Si6O18(BO3)3(OH)3FUviteCaMg3(MgAl5Si6O18(BO3)3(OH)3FHydroxy-CaFe2+3(MgAl5Si6O18(BO3)3(OH)4feruviteRossmanite(LiAl2)Al6Si6O18(BO3)3(OH)4Foitite(Fe2+2Al)Al6Si6O18(BO3)3(OH)4Magnesiofoitite(Mg2Al)Al6Si6O18(BO3)3(OH)4
A characteristic of tourmaline is that the crystal is electrically polarized on one axis of the crystal. In its natural state there is a potential difference that exists along the face of one side of the crystal. The tourmaline crystal also distorts when an electric field is placed across the crystal.
Batteries are used to supply electric energy and are well known in the arts. The standard design of a battery consists of a metallic anode, a metallic cathode, separated by an electrolyte material. The generation of electricity is accomplished by separating the reactive components so that the transfer of energy must take place through an external circuit. The anode is the cell electrode where chemical oxidation occurs. The cathode is where chemical reduction occurs in the cell. The cell electrolyte completes the electric circuit by causing the flow of positive and negative ions (called cations and anions, respectively) between the anode and cathode. (See the Chemical Engineer's Handbook, John H. Perry's, 4th edition, 1963, McGraw Hill, pp. 25-25).
A United States patent application publication to Jyoya (Mar 10, 2005, Jyoya, US 2005/0052824) describes a battery using volcanic ash and other mineral ores. This application mentions ‘other mineral ores’ including the minerals of the tourmaline group. The construction of a battery of this type provides a generating potential of 1V (unloaded), 0.5V (loaded with a external resistance of 1K) and a current of 0.5 milliamperes.
A mineral battery is described in a Japanese patent to Maeyama (18 Apr. 2002, Maeyama, 02/31895, PCT/JP00/07059). This device consists of a powder of polar crystal material with water content of more than 5 mass % in a battery housing having an outer wall and with an anode, a cathode and with respective terminals. The preferred embodiment is created from the tourmaline group.
U.S. Pat. No. 5,601,909 to Kubo (Feb. 11, 1997), describes the fabrication of tourmaline to create ‘permanent electrodes’ by creating conditions to align the crystal structures.
A polar crystal battery (hereinafter called a “polar mineral battery”) can be constructed by placing powdered polar crystal material with an electrolyte in a container, with terminals for the anode and cathode electrical connections. However, simply putting the materials together does not result in a useful battery. The present invention is a method for constructing a useful battery.